They were not the only one to make that mistake e.g. rapidjson had to fix the same error, few people expect parsing one token out of sscanf to strlen the entire input (not only that but there are c++ APIs which call sscanf under the hood).
The second error of deduplicating values by linear scanning an array was way more egregious.
GTA was never my wheelhouse, but from what I gathered GTA Online didn't have that much support, and since it was only the initial loading time, and it would have increased over time as the shop content increased, and a very fast machine (e.g. a dev machine) would have had less of an issue, the engineers working on it were probably not that incentivised to dig into it.
Like, even though it's pretty critical to initial user experience initial loading time is generally what gets disregarded the most.
> I'm pretty sure a fraction of that could afford an engineer who knows how fast computers ought to be.
It can, if someone cares enough or realises it's an issue, and then someone is motivated enough to dig into it, or has the time to.
The real, systemic error is that dozens(?) of engineers worked on that product, supposedly often testing the online component and experiencing that wait time first hand; and none thought "wait, parsing JSON doesn't take that long, computers are fast! what's going on?"
I think someone estimated that error cost them millions in revenue? I'm pretty sure a fraction of that could afford an engineer who knows how fast computers ought to be.